[tahoe-dev] [tahoe-lafs] #964: List sizes for storage using base-2 sizes, not base-10

[James A. Donald]

Tahoe-lafs wrote:
> #964: List sizes for storage using base-2 sizes, not base-10
> --------------------------+-------------------------------------------------
>  Reporter:  USSJoin       |           Owner:           
>      Type:  defect        |          Status:  new      
>  Priority:  minor         |       Milestone:  undecided
> Component:  code-storage  |         Version:  1.6.0    
>  Keywords:  usability     |   Launchpad_bug:           
> --------------------------+-------------------------------------------------
>
> Comment(by zooko):
>
>  This is what people call
>  [http://en.wikipedia.org/wiki/Parkinson%27s_Law_of_Triviality "a bike
>  shed"]. The theory goes that few people are willing to contribute their
>  opinions about designing nuclear power plants, because that is very
>  complex and requires high expertise, but many people are willing to
>  contribute their opinions about designing a bike shed, because it is
>  simple enough that they can see how they would like it to be.
>
>  ''(Aside: I don't really like that metaphor of a "bike shed" because it
>  belittles the concerns of the contributors. I actually agree with USSJoin,
>  davidsarah, and kmarkley86 that user interface issues are important,
>  including this one. Don't forget that the original post by USSJoin
>  explained how he actually lost some of his time due to confusion. Wasting
>  user time is not okay! Also, a design being simple and easy to understand
>  doesn't mean that it doesn't matter how it is done!)''
>
>  However, this issue has now distracted both David-Sarah and Brian from
>  [http://allmydata.org/trac/tahoe-lafs/milestone/2.0.0 building nuclear
>  power plants]. Let's put a stop to the discussion. Our policy will be to
>  express numbers in units that are as unambiguous as possible so that a
>  user who assumes that "GB" means 2^20^ and a user who assume that "GB"
>  means 10^9^ will both have a minimal chance of wasting their time with
>  confusion. 

I assume you meant 2^30 and 10^9

People seldom care which it is.  If they want to know the exact size, 
should be in bytes, not gigabytes.  If they do not much care about the 
exact size, should be whatever unit convenient for the implementor, or 
whatever unit the accidents of the environment cause it to wind up being.